The dinoflagellate cyst assemblages from four Lower Cretaceous sections from Melville Island, Axel Heiberg Island and Ellesmere Island in the Northwest Territories, Canada are described. The sections represent the upper part of the Isachsen Formation and the Christopher Formation. The strata studied comprise a composite stratigraphic section of approximately 1400 m of shale and siltstone deposits. The study of 33 samples yielded 83 dinoflagellate cyst species, which date the strata as late Barremian to early late Albian. The flora discussed is correlative with assemblages described from other parts of the arctic area. This study provides new and detailed palynological information about the Lower Cretaceous of the Arctic Islands. Comments are included on the morphology and ranges of: Acanthaulax sp. aff. A.? tenuiceras, Apteodinium sp. cf. A. maculatum ssp. grande, Balmula sp. cf. B. tripenta, Batioladinium longicornutum, Batioladinium shaftesburiense, Canningia reticulata, Catastomocystis spinosa, Circulodinium sp. cf. C. attadalicum, Conosphaeridium sp., Cribroperidinium sp. aff. C. conopium, Fromea triquetra, Muderongia pariata, Nyktericysta davisii, Nyktericysta? vitrea, Nyktericysta sp., Pseudoceratium sp. aff. P. toveae, Pseudoceratium sp., Rhombodella paucispina, Senoniasphaera microreticulata, Vesperopsis mayi and Vesperopsis nebulosa.